Convert codebase to use Redis for caching instead of manually caching data

[siew24]

As time goes on, it is apparent that manual caching is not feasible in terms of scalability, complexity, maintainability and stability. With the current way of caching data fetched from database, there is potential for race conditions to happen which also affects the bot's uptime.

Example of usage of Redis with Firestore

[siew24]

Turns out there's no clear-cut library for this particular context. More work will have to do to create a robust system which fetches data from Firestore and manage the data depending whether it exists in Redis or not.